NA+A2:2022 to BS EN 1997-1:2004+A1:2013

What is NA+A2 to BS EN 1997-1+A1 - General rules for UK National Annex to Eurocode 7 about?

NA+A2 to BS EN 1997 is a series on UK National Annex to Eurocode 7. UK National Annex to Eurocode 7 aims to expand on the generic contents of ISO 19650 and make it specific to the UK. NA+A2 to BS EN 1997-1+A1 gives:

• the UK decisions for the Nationally Determined Parameters (see NA.2) are described in the subclauses in the body of BS EN 1997‑1:2004+A1:2013
• the procedure to be used where alternative procedures are given in BS EN 1997‑1:2004+A1:2013
• the UK decisions on the status of BS EN 1997‑1:2004+A1:2013 informative annexes (see NA.3)
• references to non‑contradictory complementary information (see NA.4)

Who is NA+A2 to BS EN 1997-1+A1 - General rules for UK National Annex to Eurocode 7 for?

NA+A2 to BS EN 1997-1+A1 on the general rules for UK National Annex to Eurocode 7 is useful for:

• Standard designers
• Standard drafting committee

Why should you use NA+A2 to BS EN 1997-1+A1 - General rules for UK National Annex to Eurocode 7?

Together with the updated National Annex, the UK BIM Framework has also released an updated guidance document to clarify the changes. NA+A2 to BS EN 1997-1+A1 gives partial factors for geotechnical actions (γF) or the effects of geotechnical actions (γE) for ultimate limit states in the persistent and transient design situations, partial factors for soil properties (γM) for ultimate limit states in the persistent and transient design situations, partial factors for resistances (γR) for ultimate limit states in the persistent and transient design situations, correlation factors (ξ) for pile foundations and anchorages in all design situations and advice on the use of model factors. NA+A2 to BS EN 1997-1+A1 states that model factors may be applied in the derivation of the design value of resistance or the effect of an action to ensure that the results of the design calculation model are either accurate or err on the safe side.

For buildings designed using conventional calculation methods, it can be assumed that the necessary model factors are incorporated in the partial factors given in this Appendix except as specified in NA+A2 to BS EN 1997-1+A1. For bridges and other structures subject to highway loading, an additional model factor may be introduced for the evaluation of the earth pressure coefficient K, see PD 66941. Additionally, where the method of analysis of a building or a bridge is innovative, or where the results of a calculation are of uncertain reliability, model factors may be applied. In such cases, the values should be agreed upon with the client and relevant authorities. In selecting the values of a model factor, the principles described in BS EN 19971:2004+A1:2013. Model factors required in pile design are provided in NA+A2 to BS EN 1997-1+A1. Using NA+A2 to BS EN 1997-1+A1 you can specify general rules for the geotechnical design of a UK National Annex to Eurocode 7.